In another thread lately, I mentioned that I had a batch of 5.56mm reconditioned cases that I bought some years ago. They were advertised at "prepped." They are beautiful, obviously liquid tumbled with pins. When I first got them, I ran about a dozen through a cartridge headspace gauge and they were either uniquely uniform as a batch or had been trimmed. The primer pockets were swaged. Aside from giving the case mouths a slight chamfer, I assumed they were ready to go. I have been storing these in a big, round, metal tin. I'd thought there were 1,000 in there; my markings on the outside say 500. However, after removing 100 tonight, I may be wrong about the 500. There actually may be 1,000 there. Also, I'd remembered them as Federal, they are LC's with three different dates.
After mentioning these the other day, I decided to get into them. Who or what was I saving them for? I have some Hornady 75 gr. Interlock HD bullets that I want to try out. I gave the cases a bit of a chamfer at the mouth, then I primed them with CCI 450's. I got my seating die calibrated to the work and set up to charge with BL-C(2) powder. Then I got into seating the bullets. Right away I could tell something wasn't quite right. The bullets seated hard, yet had insufficient tension. I struggled along and loaded about 30 pieces then I stopped and thought, "This just isn't right." Close examination of the cartridge showed that the case mouth had a slight, offset bulge where the bullet was seated. I miked a few of the bullets, they were right on at .224. I rolled one of the loaded rounds along the bench, and I could see the bullet was slightly askew, out of concentricity, whatever you'd call it. Next I got a few cases that I'd prepped myself at some earlier time, and loaded some of the 75 gr. bullets into them. Those loaded just right, with appropriate resistance when seated, yet having good bullet tension. They rolled across the bench without any degraded concentricity. So my shiny, store-bought cases had to be the culprit.
They were. What I found was that the case mouths hadn't been sized correctly. My guess is, whoever "prepped" these did not use a sizing button. That's the little ball on the end of the decapping pin that does the final sizing of the case mouth. The die body does the initial size-down, then the button gives it the final size on the up-stroke. The case mouths were too small. When a bullet was attempted to be seated, it deformed the case mouth. This deformity not only caused the bullet to be slightly skewed, but warped the brass mouth in a way that disallowed uniform tension on the bullet, and that's how I wound up with loose bullets in a tight case mouth. This seemingly contradictory situation sounds illogical but that's what happened.
This wouldn't happen with a 7.62mm NATO or .30-06 case. Because the brass material is thicker than the 5.56mm. I've loaded .309 bullets into .30-06 before without any of this.
During the course of figuring this out, I used two different bullet seating dies. One, an RCBS standard seating die. When I started having issues, I changed to a Hornady "precision" seating die, the kind with the long sleeve that comes down and supposedly guides the bullet into the case mouth better. No change.
I can't remember now where I bought these. Being Lake City, they are dated and the newest one is 2016. Using the sizing button (only) on my own sizing die, I opened up the mouths of the 100 I was working on. BUT: I have all the rest of those remaining in the tin to do as well.
They were supposed to be "once fired." I found several with the four little stake marks around the primer pocket that some ammo remanufacturers use. Tumbling with pins is an equalizer.
After mentioning these the other day, I decided to get into them. Who or what was I saving them for? I have some Hornady 75 gr. Interlock HD bullets that I want to try out. I gave the cases a bit of a chamfer at the mouth, then I primed them with CCI 450's. I got my seating die calibrated to the work and set up to charge with BL-C(2) powder. Then I got into seating the bullets. Right away I could tell something wasn't quite right. The bullets seated hard, yet had insufficient tension. I struggled along and loaded about 30 pieces then I stopped and thought, "This just isn't right." Close examination of the cartridge showed that the case mouth had a slight, offset bulge where the bullet was seated. I miked a few of the bullets, they were right on at .224. I rolled one of the loaded rounds along the bench, and I could see the bullet was slightly askew, out of concentricity, whatever you'd call it. Next I got a few cases that I'd prepped myself at some earlier time, and loaded some of the 75 gr. bullets into them. Those loaded just right, with appropriate resistance when seated, yet having good bullet tension. They rolled across the bench without any degraded concentricity. So my shiny, store-bought cases had to be the culprit.
They were. What I found was that the case mouths hadn't been sized correctly. My guess is, whoever "prepped" these did not use a sizing button. That's the little ball on the end of the decapping pin that does the final sizing of the case mouth. The die body does the initial size-down, then the button gives it the final size on the up-stroke. The case mouths were too small. When a bullet was attempted to be seated, it deformed the case mouth. This deformity not only caused the bullet to be slightly skewed, but warped the brass mouth in a way that disallowed uniform tension on the bullet, and that's how I wound up with loose bullets in a tight case mouth. This seemingly contradictory situation sounds illogical but that's what happened.
This wouldn't happen with a 7.62mm NATO or .30-06 case. Because the brass material is thicker than the 5.56mm. I've loaded .309 bullets into .30-06 before without any of this.
During the course of figuring this out, I used two different bullet seating dies. One, an RCBS standard seating die. When I started having issues, I changed to a Hornady "precision" seating die, the kind with the long sleeve that comes down and supposedly guides the bullet into the case mouth better. No change.
I can't remember now where I bought these. Being Lake City, they are dated and the newest one is 2016. Using the sizing button (only) on my own sizing die, I opened up the mouths of the 100 I was working on. BUT: I have all the rest of those remaining in the tin to do as well.
They were supposed to be "once fired." I found several with the four little stake marks around the primer pocket that some ammo remanufacturers use. Tumbling with pins is an equalizer.
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